1. Technical Field
The present disclosure relates to an imaging apparatus.
2. Description of Related Art
An imaging apparatus generally includes a number of lenses and an imaging sensor. The imaging apparatus focuses by changing the distance between the lenses. Referring to FIG. 7, a typical imaging apparatus 100 is shown, and includes a first lens 11, a second lens 12, a third lens 13, a fourth lens 14, an image sensor 16, and a driving device 17 aligned from an object side to an image side of the imaging apparatus 100. The first lens 11 and the third lens 13 each have a positive refractive power; the second lens 12 and the fourth lens 14 each have a negative refractive power. The driving device 17 is configured for providing a driving force to the first lens 11 to change the focus setting of the imaging apparatus 100, for example, from a general infinite focus setting to a close-up focus setting. When changing infinite to close-up focus setting, the first lens 11 needs to be moved toward the object side of the imaging apparatus 100.
However, with the above configuration, because the first lens 11 is the outermost lens, when it is moved back and forth in the barrel, it first exposes portions of the barrel, which can collect dust, then encloses those portions so that the dust may penetrate the imaging apparatus. To avoid this, the second lens 12 could be moved instead of the first lens 11, however, movement directions of the lens 12 would be different than the lens 11 and require redesign of the driving device 17 which is difficult and costly.
What is needed therefore, is an imaging apparatus which can overcome the above-mentioned problems.